The present disclosure relates generally to well drilling operations and, more particularly, to detection and location of proximate well casings during drilling.
Hydrocarbons, such as oil and gas, are commonly obtained from subterranean formations that may be located onshore or offshore. The development of subterranean operations and the processes involved in removing hydrocarbons from a subterranean formation are complex. Typically, subterranean operations involve a number of different steps such as, for example, drilling a wellbore at a desired well site, treating the wellbore to optimize production of hydrocarbons, and performing the necessary steps to produce and process the hydrocarbons from the subterranean formation.
During drilling operations of hydrocarbon producing wells, it may be necessary to drill a wellbore with a location and geometry dependent on an existing wellbore. For example, in Steam Assisted Gravity Drainage (SAGD) drilling operations, a production well is typically drilled though a formation horizontally and a steam injection well is then drilled to be a given distance above the production well, e.g., five meters above the production well. Steam is then injected into the steam injection well to raise the temperature of surrounding hydrocarbon-containing formation. As the hydrocarbon-containing formation is heated, the viscosity of surrounding hydrocarbon may decrease and/or surrounding hydrocarbons may flow from the formation into the production well. This SAGD production system has been used to produce hydrocarbons too viscous to be produced as a liquid or gas in its natural state. For example, hydrocarbon-containing compounds have been produced from bituminous sands (or “tar sands”) using an SAGD system.
In addition, in some well intervention operations a second wellbore may be required that intersects and/or connects with a first wellbore. For example, a second wellbore may be used to relieve pressure on the first wellbore, direct fluids away from the first wellbore, and/or otherwise intervene with the first wellbore when access from the surface is unavailable. To accomplish this interfacing of two wellbores within the formation, the first well typically must be located within the formation to determine the location of the second well.
For drilling operations where the location of the drilled wellbore depends on the location of another wellbore, it is desirable for a drilling operator to have the ability to determine the distance and/or location of a proximate wellbore and make adjustments to the drilling operation as a result.
While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.